Anthraquinone aldehyde and process of making same.



- UNITED STATES PATENT OFFICE.

MAX HENRY ISLER, OF MAN NHEIM, GERMANY, ASSIGNOR TO .BADISCHE ANILIN & SODA FABRIK, OF LUDVVlGSHAFEN-ON-THE-RHINE, GER- MANY, A CORPORATION.

Specification of Letters Patent.

Patented Aug. 14, 1906.

Application filed February 16, 1908. Serial No. 301,452.

To. all whom it 'nuty coz ccrn:

Be it known that I, MAx HENRY ISLER, chemist, a citizen of the Swiss Republic, residing at Mannheim, in the Grand Duchy of Baden, German Empire, have invented new and useful Improvements in Anthraquinone Aldehydes, of which the following is a specification.

My invention relates to the production of a new class of chemical compounds-namely, the aldehydes of the anthraquinone group.

In the specification of application for Letters Patent, Serial No. 301,451, filed February 16, 1906, is described the roduction of omega-halogen derivatives 0 2-methyl-anthraquinone compounds by acting on these latter compounds with a halogeniz'ing agent. I have now discovered that the omega-dihalogen derivatives of 2-methyl-anthraquinone compounds can by treatment with concentrated sulfuric acid, with or without the adgeneric properties an in particular gives a yellow solution in concentrated sulfuric acid and is insoluble in caustic-soda solution and on suitable oxidation yields the 2-anthraquinone carboxylic acid.

The following examples will serve to further illustrate the nature of my invention and how it can be carried into practical ef: feet; but my invention is not confined to these examples. The parts are by weight.

Example 1: Heat to other one (1) part of omega-dichlor-Z-methy anthraquinone and ten (10) parts of ninety-seven (97) per cent.

sulfuric acid at a temperature of one hundred andthirty (130) degrees centigrade for from five (5) to six (6) hours or until a test portion when diluted with water and washed free from acid contains no halogen. Then pour the melt into water and filter ofi and wash the precipitate. The 2-anthraquinone aldehyde can be further purified by crystallizing it from alcohol. On treatment with oxidizing agents it is converted into anthraquinone carboxylic acid. I I

Example 2: Heat together one (1) art of the omega-dibrom derivative of 1-0 lor-2- methyl-anthraquinone, ten (10) parts of ninety-seven (97) per cent. sulfuric acid, and one (1) part of anhydrous boric acid for from six (6) to seven (7) hours at a temperature of one hundred and thirty (130) degrees centi grade and isolate the '1-chlor-2-anthraquinone aldehyde in the manner described in the foregoing Example '1.

Example 3: Heat together one (1) part of the omega-dibrom derivative of 4-brom-1- hydroxy-2-methyl-anthraquinone, ten (10) parts of ninety-seven (97 per cent. sulfuric acid, and one (1) part of anhydrous boric acid for from five (5) to seven (7) hours at a temperature of one hundred and thirty (130) degrees centigrade. From the melt 4-brom- 1-hydroxy-2-anthraquinone aldehyde can be isolated in the manner given in the fore oing Example 1. It is soluble in caustic-so a solution, with a violet-red color.

Now what I claim is- I 1. The process for the production of aldehydes of the anthraquinone series by heating an omega-dihalogen derivative of a 2-methylantgiraquinone with concentrated sulfuric 2101 2. The process for the production of aldehydes of the anthraquinone series by heating an omegad halogen derivative of a Z-methylanthraquinone with concentrated sulfuric acid and boric acid.

3. The process for the production of 2amthraquinone aldehyde by heating omegl; dichlor-2-methyl-anthraquinone with sul ric acid.

4. As new articles of manufacture the aldehydes of the anthraquinone group which can be obtained by heating an omega-dihalogen derivative of a 2-methyl-anthra uinone with concentrated sulfuric. acid, whic aldehydes are soluble in concentrated sulfuric acid yielding from yellow to yellowish red solutions, and in anilin yielding reddish-yellow solutions and are also soluble in alcohol and compound soluble in concentratcd sulfuric in glacial acetic acid-and upon oxidation can which upon oxidation can be converted into be converted into an hraqiiinone carboxylic anthraquinone carboxylic acid.

. acids. In testimony whereof I have hereunto set v .5. As .a new article of manufacture Z-anmy hand in the'presence of two subscribing 5 thr'aquinone-aldehydb which. is a crystalline Witnesses.

acid-yielding a yellow solution and in .anilin MAX HENRY ISLER' yieldin a reddish-yellow solution and which Witnesses: is solub e in alcohol and in glacial acetic acid J. ALEC. LLOYD, lo and insoluble in caustic-soda solution and J 0s. LEUTE. 

